Temporal trend studies on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ringed seals from east Greenland.

The concentrations of polybrominated diphenyl ethers ( PBDEs) 17, 28, 47, 49, 66, 85, 99, 100, 153, 154, and 183 were determined in ringed seal blubber from central East Greenland collected in 1986, 1994, 1999 and during the period 2001 to 2004. The trend of PBDEs was compared with the trends of polychlorinated biphenyls ( PCBs) 28, 31, 52, 101, 105, 118, 138, 153, 156, and 180 during the same period. The levels of SPBDE in East Greenland ringed seals ranged from 21.8 ng g(-1) lipid weight ( lw) in 1986 to 39.3 ng g(-1) lw in 2001 and are among the highest observed in ringed seal from the Arctic. The dominating congeners were BDE-47 ( 75.4%) and BDE- 99 ( 9.7%). The concentrations of PBDEs and PCBs increased with the age of the seals, and therefore only young seals ( <= 4 years old) were included in the temporal trend analyses. No significant trend ( p > 0.14) was observed in SPBDE or the congeners BDE 28, 47 and, 99 during the period while SPCB decreased significantly ( p = 0.004) over the period from 1986 to 2004 with an estimated annual rate of 4.3%.